Research has shown that HIV infection impairs cognitive functioning to varying degrees and these impairments tend to increase as the disease progresses. In fact young HIV Infected individuals show cognitive impairments similar to those occuring with natural aging. To date there is limited understanding of the impact of HIV infection on the cognitive functioning of older adults and the implications of HIV infection and aging on the performance of real world tasks. Preliminary data suggests that older HIV infected adults may be at increased risk for cognitive impairment due to the joint effects of aging and disease. The objectives of this study are to examine the impact of HIV infection on the cognitive functioning of older adults and gather information on how aging and HIV infection impact the performance of real world cognitive tasks. A sample of 45 people between the ages of 50-65 years will participate in the study. There will be 15 subjects from each of three groups. HIV-1 negative, HIV-1 positive (early symptomatic stage), HIV-1 positive (late symptomatic stage). The sample will participate for two days. They will complete a cognitive battery and be trained to perform a real world computer task. Data will include measures of task performance (speed and accuracy) and measures of fatigue and stress. Group differences on measures of cognitive ability and task performance will be examined as well as the relationship between cognitive ability and task performance. The overall goal of the study is to gather information regarding the potential impact of HIV infection on the quality of life of older adults.